Synthetic transmembrane components

Abstract

The invention relates to nucleic acids encoding a synthetic transmembrane region as well as to membrane associated proteins containing these synthetic transmembrane regions. The design of the synthetic transmembrane region allows various properties of a protein, such as its level of expression, and relative response to ligand binding to be tailored as required for a specific purpose.

Description

[0001]This application is a U.S. National Stage Application of PCT Application No. PCT / GB00 / 01476, filed Apr. 17, 2000.[0002]The present invention relates to nucleic acids encoding synthetic polypeptides, the use of these polypeptides as discrete domains within a chimeric protein and to the use of such chimeric proteins in medicine and research.[0003]The number of industrial and medical applications involving protein products and / or targets has increased considerably over recent years. This has resulted in a corresponding increase in the use of protein engineering to improve the existing (or to create novel) structural or functional characteristics of a protein.[0004]In order to produce a successfully engineered protein, the changes that are introduced must be compatible with each other and the remaining structural and functional features of the protein. Although this process can be facilitated by knowledge of the three-dimensional structure, or by rational design based on predicted...

AI Technical Summary

Benefits of technology

"The patent text describes the use of a synthetic polypeptide as a transmembrane domain in a membrane-associated protein. This can have unexpected effects on the properties of the protein, including its sensitivity to antigen and the level of expression. The choice of synthetic transmembrane region can also affect the response function of the protein to different types of antigen. The patent also provides a method for assessing the level of expression of the protein. Overall, the invention allows for precise tailoring of the response function of the protein and optimizes the activation of the signalling cascade within the cell."

Problems solved by technology

Although this process can be facilitated by knowledge of the three-dimensional structure, or by rational design based on predicted molecular models of the protein, success is not guaranteed and is difficult to achieve.

A problem exists with the previously described chimeric receptor proteins in that they are susceptible to signalling not only in response to cell surface bound ligand, but also in response to the presence of soluble antigen.

This is a particularly undesirable characteristic of a chimeric receptor and can limit the therapeutic potential of this approach (Eshar, Z.

Many antigens that would otherwise make attractive targets for chimeric receptor-based therapy are thus unsuitable because they are either shed from the surface of cells or they are secreted.

The therapeutic use of chimeric receptors with specificity for this type of antigen ligand could be severely compromised by the presence of a circulating antigen component.

This would not only lead to reduced efficacy but could potentially cause systemic toxicity due to the inappropriate release of cytokines.

An additional issue with chimeric receptors is presented by the poor understanding of the mechanisms by which these proteins convert the extracellular binding of ligand to receptor into intracellular signalling events.

However, it is not possible to define precisely the level of receptor expression using such a method, since the efficacy of all promoter systems tends to vary between different cell types and under different physiological conditions.

Furthermore, the use of strong promoter systems can be physiologically disruptive when used in vivo.

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